The certified flight instructor (CFI) reported that she and her student planned to perform a series of takeoffs and landings at the airport. Their first takeoff occurred about 1410, and the CFI requested and received an air traffic clearance to remain in the pattern. The airplane's anti-collision light was operating. The lowest layer of clouds was located about 2,800 feet above ground level, and the visibility was 25 miles. There was light turbulence in the area. About 1430, after making three touch-and-go landings, the air traffic controller requested that the pilot fly an extended downwind leg. The CFI stated that "shortly thereafter, we noticed a red-tail hawk slightly ahead and at our same altitude. Upon sighting the bird, I immediately took control from my student and initiated a climbing turn to the left. A few seconds later we heard a loud impact on our right wing tip. I immediately looked out the window and noticed the wing had extensive damage." The CFI reported that she immediately landed, and during the approach she did not detect any noticeable effect on the airplane's performance. Regarding the extent of the damage, the flight school's director of maintenance reported that the outboard span of leading edge wing skin, immediately inboard of the wing tip, was crushed about 8 inches in an aft direction. In this area, an outer wing rib was cracked, and two ribs were bent. The span of the deformation was almost 3 feet, and a major structural airframe repair was required to fix the damaged wing. No residue of the impacted bird was found. Several photographs (included in the docket for this report) were provided to the National Transportation Safety Board by the airplane rental company, Golden State Flying Club, El Cajon, California.